1. Field of the Invention
The present invention relates generally to an electrical locking/unlocking system and more specifically to an electronic unlocking system by which a door can be unlocked when a single switch is depressed repeatedly by a driver in time with a musical rhythm which he knows, for instance, or in accordance with a Morse-type code.
2. Description of the Prior Art
As is well-known, electrical locking/unlocking devices have been proposed by which, for instance, a door can be locked or unlocked by depressing a plurality of push-button switches in a predetermined sequence; however, in this type of electrical locking/unlocking devices, since a switch board on which a plurality of push-button switches are arranged must be disposed near the door, and further since the different push-button switches must be depressed repeatedly, there exist such shortcomings that there are relatively few places where the switch board can be mounted and the repeated operations of different push-button switches are troublesome because the operator must repeatedly locate the appropriate switches. In order to overcome these problems, although it is possible to lock or unlock a door by simply depressing a single switch, this type of electrical door locking/unlocking device is not practical from the standpoint of crime prevention because a thief can easily unlock the door.